chronic stable angina

Introduction

Commonly, referenced as angina.

Etiology

• coronary artery disease
  • cardiovascular risk factors
• aortic stenosis
• hypertrophic cardiomyopathy
• pharmaceutical causes: (exacerbation)
  • alpha blockers
  • beta blocker withdrawal
  • ergotamine
  • hydralazine
  • methysergide
  • minoxidil
  • nifedipine
  • oxytocin
  • thyroxine (excessive)
  • vasopressin

Epidemiology

• 5-7% of population from 44 to 75 years of age
• risk increases with age

Pathology

• myocardial ischemia secondary to reduced blood flow through partially obstructed coronary arteries

Clinical manifestations

• steady precordial pressure or pain
• induced by exercise, emotion, or eating
  • at least 2 months duration
• radiation to the jaw or left shoulder & arm
• duration of pain < 20 minutes
• dyspnea, especially female, diabetic, elderly
• diaphoresis
• fear of death
• nausea
• relief by nitroglycerin or rest
• palpable precordial apical bulge that disappears with pain
• signs of congestive heart failure (CHF) may be present
• 4th heart sound
• mitral regurgitant murmur secondary to papillary muscle dysfunction

Laboratory

• fasting lipid panel

Diagnostic procedures

• electrocardiogram (ECG):
  • ST segment depression during pain
  • T wave changes (inversion) during pain
  • Q waves suggest prior MI
• exercise treadmill
  • able to exercise
• normal ECG or non-interfering ECG changes
  • complete RBBB ok
• echocardiogram:
  • previous MI, or Q waves on ECG
  • heart failure
  • LBBB not ok
• exercise echocardiography
  • pre-excitation (WPW)
  • LBBB
  • ST segment depression > 1 mm
  • previous revascularization

Radiology

• stress tests
  • graded exercise test with or without thallium or sestamibi scintigraphy
  • dipyridamole thallium test or dobutamine echocardiogrqphy
    • severe arthritis
    • morbid obesity
    • stroke
    • peripheral arterial disease
    • pacemaker: electronically paced ventricular rhythm
  • patients with stable angina with good exercise tolerance are low risk unless imaging demonstrates left main coronary artery disease or multivessel coronary artery disease
• coronary CT angiography may useful in emergency department setting*
  • lessens need for coronary angiography in intermediate risk patients with chest pain
  • associated with lower risk for myocardial infarction but not mortality compared with exercise stress testing
  • improved clinical outcomes at 5 years in patients with chest pain
• coronary angiography & percutaneous coronary intervention (PCI)*
  • LV dysfunction
  • NYHA class 3 or class 4 angina, despite optimal therapy
  • positive stress test or uncertain diagnosis after stress test
  • high probability of left main coronary artery or 3-vessel disease
  • survivors of sudden cardiac death
  • suspected coronary vasospasm (Prinzmetal's angina)
  • does not decrease mortality or risk for MI
• multidetector CT shows promise

* no significant differences between CT angiography & coronary angiography with PCI in cardiovascular-related death, myocardial infarction, or stroke during 3 1/2 year follow-up

Complications

• women with angina pectoris, but mild or no obstruction on angiography, are not clear of cardiovascular risk

Differential diagnosis

see chest pain

Management

• general
  • patients with stable angina with good exercise tolerance are low risk unless imaging demonstrates left main coronary artery disease or multivessel coronary artery disease
• risk factor (life style) modification
  • smoking cessation reduces risk of coronary artery disease by 50% within 5 years of quitting
  • aerobic exercise
  • weight loss: maintenance of ideal body weight reduces risk of coronary artery disease
  • control of hypertension
    • BP < 140/90, 130/80 if diabetic
  • control of diabetes
    • include SGLT2 inhibitor (flozin) or GLP1-receptor agonist (glutide)
  • dietary intervention
    • reduction in calories
    • reduction in total & saturated fat
    • reduction in cholesterol
    • reduction in sodium may be appropriate
    • antioxidants have been suggested to have benefit
    • Mediterranean diet, DASH diet
• pharmaceutical agents
  • beta-adrenergic receptor antagonists (all patients)
    • decrease heart rate & myocardial contractility
      • achieve heart rate of 55-60/min
    • useful in exercise-induced angina
    • cardioselective beta blockers are preferred agents (not according to NEJM)
      • atenolol
      • metoprolol
      • no need to replace carvedilol with metoprolol
    • contraindications
      • asthma
      • symptomatic bradycardia
      • heart failure
      • severe peripheral arterial disease
  • aspirin (all patients)
    • 75 to 325 mg QD
    • effective in secondary prevention of coronary artery disease in patients with angina
    • clopidogrel if aspirin intolerant
  • nitrates
    • beta-blocker not sufficient to relieve symptoms
    • reduce preload & afterload
    • dilate coronary arteries
    • daily nitrate free interval of 8-10 hours
    • may cause headaches
    • sublingual nitroglycerin
    • isosorbide (long-acting)
    • transdermal nitrates
  • calcium channel blocker
    • beta-blocker cannot be used or is not sufficient to relieve angina
    • increase coronary artery perfusion
    • diminish afterload
    • diltiazem or verapamil suggested except if LV systolic dysfunction
      • amlodipine ok for relief of angina
    • do not use short-acting calcium channel blocker (nifedipine ..)
  • ACE inhibitor
    • LV ejection fraction < 35%
    • stroke, CAD, or peripheral artery disease
      • no proven value in chronic stable angina
    • diabetes, chronic renal failure
    • additional cardiac risk factors
      • history of myocardial infarction
      • calcium channel blocker in use
  • statin (all patients)
    • target LDL < 100 mg/dL
    • clinical factors may stratify risk to identify patients for high-dose statins
  • ranolazine if other options exhausted
    • calcium channel blocker in use
• adjunctive therapy with acupuncture may be of benefit
• revascularization for persistent symptoms despite maximal medical therapy
  • percutaneous transluminal angioplasty
    • improves quality of life
    • does not improve survival or reduce cardiovascular events
  • coronary artery bypass graft (CABG)
    • reduces of mortality (RR=0.80), myocardial infarction, & need for subsequent revascularization, compared with medical management
    • CABG preferred to PCI for left main with LV systolic dysfunction or 3-vessel disease or multivessel disease with diabetes mellitus
• refractory angina pectoris not amenable to revascularization
  • enhanced external counterpulsation
  • spinal cord stimulation of the region that receives cardiac nerve fibers diminishes angina & improves functional status
• routine screening in asymptomatic patients not indicated

More general terms

• angina pectoris
• chronic heart disease

Additional terms

• acute coronary syndrome; unstable angina (ACS)
• Prinzmetal's angina; variant angina; coronary vasospasm